Pulverizing machine



Jan. 28, 1930. P? sc 1,744,895

PULVERIZING MACHINE Filed Nov. 15, 1928 3 Sheets-Sheet 1 INVENTOR.

A TTORNEYS I Jan. 28, 1930. P. A. HIRSCH PULVERIZING MACHINE 3Sheets-Sheet 2 Filegi Nov. 15. 1928 INVENTOR."

BY W I ATTORNEYS.

Patented Jan. 28, 1930 PATENT OFFICE PAUL ARTHUR. mason, or New YORK, N.Y.

PUL'V'ERIZING- MACHINE Application filed November 15, 1928. Serial No.319,620.

This invention is a novel pulverizing machine, and relates-particularlyto a pulverizer of the so-called impact type and designed forpulverizing coal or any other fuels or ma- 5 terials to an extremelyfine degree of reduction; the impact type referring to a principle ofreduction wherein the particles are acted upon by the reducing membersor beaters while carried along in a flow of air, as distinguished from acrushing between two machine parts. v

The present invention is herein shown embodied in a pulverizing machinehaving a chambered casing with an operating shaft therein and beaters orpaddles revolved by the shaft, while axial air flow causes progressiveadvance of the material being reduced; although certain features hereofmight be otherwise embodied. The illustrated construction of pulverizingmachine is adaptable for the very fine reduction of coal, for examplefor the purpose of direct feed to a fire or furnace in suspension inair, thus dispensing with the need of storage bins for the pulverizedfuel. Prior pulverizers of the class and for the purpose referred to areillustrated in certain patents heretofore issued to me, includingPatents No. 1, 17 9,540 of January 1, 1924 and No. 1,636,693 of July 26,1927; the present invention'being in some aspects an improvement on saidprior patents and in other aspects being directed to independentlyuseful features of invention.

The general objects of the present invention are to afford increasedefficiency of pulverization, with an enlarged rate of output, anda highdegree of fineness of pulv'erization, and uniformity thereof. Furtherobjects are to minimize power consumption and to reduce wear, thusprolongingthe life of the machine, while rendering thewear parts readilyreplaceable. Other and further objects and advantages will be explainedin the hereinafter following description of one or more embodimentsthereof or will be understood to those skilled in the subject.

To the attainment of the objects and advantages referred to the presentinvention consists in the novel pulverizing machineand the novelfeatures of operation, combination,

arrangement and construction herein illus trated or described.

In the accompanying drawings Fig. 1 is a substantially central. verticalsection of a pulverizing machine illustrating the present invention.

Fig. 2 is a combined right elevation and section, the section beingshown taken at three different planes indicated by the lines 2*, 2 and 2of Fig. 1.

Figs. 3 and 1 are detail perspective views of certain interior parts.

Fig. 5 is a diagrammatic view or development of the successive series ofrotary pulverizing elements or beaters and the non-rotating elementsbetween them.

Figs. 6 and 7 are developments similar to Fig. 5, but showingmodifications as to certain of the elements. 1 I

Referring in detail to the illustrated structure the pulverizing machineis shown of the horizontal type, although it may in some cases bearranged vertically. The machine is supported by legs or hollow baseportions 10 at the corners and other similar supporting extensions. Thecylindrical casing or drum 11 is supported on such base parts and ispreferably fixed against rotation. It is shown constructed in upper andlower halves, these being connected to eachother at both the front andrear sides of the machine by hinge extensions 12 engaged by bolts 13, bywhich arrangement either bolt may be removed to unlock the casing,permitting the latter to be swung open at eitherfront or rear. The lowercasing half is shown as formed with four drop extensions 14, each ofwhich is hollow and is adapted to receive pieces of metal and otherforeign matter and is closed bya removable cover 15.

The drum or casing at its right end is shown closed by a circular endwall or head 17. This may be cast integral with two of the supportinglegs 10 and may have an upward feed extension 18 by which fuel is fed tothe pulverizer. The mode of feed and regula tion of fuel may be asexplained in said rior patents or otherwise. The inlet head as a passageextending downwardly from the feed extension and delivering throughaperture being suitably regulated. The inlet head 17 is shown as formedwith a shelf 21 for a shaft hearing as will be described.

At the other end of the drum or casing is a discharge head 23 secured tothe drum and having a central or axial, and preferably concentric,outlet or discharge opening 24. The head 23 may be extended integrallyat 25 to form a fan casing, this being of usual shape with tangentialoutlet or delivery 26'. The fan chamber at its outer wall may have acentral air inlet 27 fed from an air box or duct 28 supplied either withatmospheric air or preheated air preferably under control of a damper.Adjacent the fan casing is shown a pedestal or shelf 29 for supporting ashaft bearing.

The machine is preferably operated through a central shaft 32 supportedat the inlet end by a bearing 33 and at the outlet end by a bearing 34resting respectively on the shelves 21 and 29. The shaft may be powerrotated in any usual Way and a clutch 35 is conventionally illustratedas a means of coupling and uncoupling the shaft.

Within the fan chamber 25 is shown a fan which may be of known form, forexample substantially like that illustrated in my prior application112,956. The fan is divided into separate portions. The coal unit 38consists of blades supported on a web 39 extending outwardly from a hub40 which is of a concavely curved shape to facilitate the smooth flow ofthe outgoing stream of fuel-laden air. The air unit 41 comprises bladesmounted on a web 42 turning with a hub 43 concavely curved to facilitatethe flow of air from the inlet 27 through the fan casing The two hubsare secured to the shaft 32 and cause a whirling delivery of the fueland air streams which combine and pass outwardly at 26.

Preferably a plurality of beating or reduction units are employed, andthree are shown. The first beating unit comprises a hub 46 secured onthe shaft, this having opposed webs 47 which are cross connected neartheir peripheries by a series of studs 48 serving as supporting pins forthe beatingelements. A wear plate 49 is shown attached in position toprotect the elements 46, 47 and 48 from the wear of the incoming fuel.The beating elements may be in the form of swinging hammers 50, eachcontacting against a stud 48 and there held by a U- shape piece orstirrup 51 secured to the hammer by bolt 52. During the high speedrotation of the described reduction unit the hammers are capable ofswingingly yielding, thus avoiding breakage in case of unduly largeparticles or obstructions.

The second heating unit is spaced from the first and the third is spacedfrom the second, and between each two of the successive beating unitsare arranged certain stationary parts to be described, so that in asense each beating unit may be said to rotate within a definite space orreduction chamber. The second unit is shown as comprising a hub 54secured on the shaft with a web 55 in the form of a closed disk andhaving near its periphery a transversely extending wall or ring whichmay conveniently be built up by the provision of two flanged rings 56attached by bolts 57 at the opposite sides of the disk or web, withtheir flanges in substantial axial alinement. The rings 56 or theflanges thereof are shown as interrupted or recessed to receive theshanks of the beating elements or hammers. In this case as indicated inFigs. 1 and 5 there are two series of hammers 58 and 59, the formeroccupying the first half of the chamber and the latter the second halfthereof, in staggered relation. This construction and arrangement ofbeating hammers is found'to afford a more effective degree of impact andattrition of the floating particles.

The third heating unit is substantially identical with the second but,as indicated in Fig. 5, the heaters or hammers 58" and 59 are preferablymore numerous and more closely spaced than in the case of the hammers 58and 59.

Certain features of construction and operation herein are similar tosaid prior patents of 1924 and 1927. Thus it will be observed that thedrum or casing 11 has no peripheral egress at any point. The outlet isof contracted diameter and the inlet does not reach to the periphery. Itis' therefore possible by high speeds to develop a high centrifugalpressure along the peripheral travel of the materials. F ollowing eachbeating unit or set of hammers is shown a whirl obstructing element inthe form of a series of blade-like vanes, relatively stationary, and soarranged or flow through the pulverizing machine in spite of high speedand centrifugal pressure. In the drawings the shaft 32 is shownhorizontal, but the entire machine might be turned at right angles thatthe axial progress of the material will be either upwardly or downwardlyas may be rendered desirable by any particular conditions.

The first whirl obstructing unit or vane unit is shown immediatelysucceeding the first reduction unit. It comprises a set of vanes 61which may extend axially, by which is meant that the planes of thesevanes either extend through the general axis'of the machine or parallelthereto, although they might be somewhat slanted as and for the purposesto be described in connection with the second vane unit herein. Theseveral vanes 61 are shown supported by an outer rim 62 having a bead 63which is fixedly secured by screws 64 to the casing or'drum 11. Thecomplete vane unit may be split'in upper and 4 lower halves so as topermit opening and closing of the casing without detachment of thescrews 64. The vanes 61 may be relative- 1y short in a radial direction,terminating at approximately the inner reducing zone, and theinner endsof the vanes the webs 47 of the first beating unit.

are shown as interconnected by an inside rim 66 which is integrallyextended asa webor disk 67 reaching substantially to the shaft 32 andhaving a side flange 68 overlying onenef e vanes 61 and the outer andinner rims con necting them may be cast in a single cast-mg with the web67, as indicated in Fig. 3. The

- unit or set of vanes 61 ,may be considered as relatively stationary,meaning that they, do not rotate with the shaft and beating units.

4 In their function of' diverting heavier particles and throwing themback from the advancing flow the vanes constitute a selective orseparating device.

It will be noted thatthe inner rim 66 is substantially in alinement withthe flange or rim portions of the rings'56 of the succeeding reducingelement so that these parts, ar-- a generally axial or cylindricalranged in manner, constitute a means or barrier for confining theadvancingwfuel near to the lining of the casing, these rims and thelining enclosing-what may be termed the reduction zone or that portionof the periphery which is subject to the action of the beaters orhammers. The material therefore is forced to advance through the machinewithout escaping, but subject to, the action of the successive heatingunits and successive vane units.

' The second vane unit comprises a system 0 vanes 71 which as indicatedinFigs. 1, 2, 4 and 5 have a slant, or a greater slant than the vanes61, and the vanes 71 are preferably more numerous. The slant orinclination of the vanes 71 is in relation to. an axial direction orplane and the slant is a reversing slant so as to produce an actiontending eflectively limit of the second" clude the possibility of flowinside the rim.

\ Following the third'reduction chamber is similarly shown a third setofvanes 81. This however, being the final set, is of special structureand arrangement. The vanes 81 are substantially slanted and may be asnumerous or more numerous than the vanes 71. Alternate vanes 81 of thethird set however are shown as continued as axial extensions 81 which,as seen in Fig. 1, are extended inwardly at least to the edge of theoutlet opening 24, so as to facilitate the spread of the flowing-materials inwardly to the outlet. The several vanes 81, 81 and 81 areshown formed with and supported by an outer rim 82 which is of specialshape to fit the corner of the casing and is held by screws 84. There isalso shown an inside rim 86 in substantial alinement with the rims 66and 76 already mentioned and having an inwardly extendin web 87, theinner portion of which is curved :around at 88 into substantial circularalineterior recess in the outlet head 23, and this lining piece may haveradial ribs 91 in alinement with the vanes 81*; The casing 11 isprotected from directwear by a system of lining pieces 94. These may besquare flat pieces of cast iron, each confined endwise between theseveral outer rims 62, 72 and 82 and the casing. Each half circle ofthese lining plates may be confined within the half-casing by theconfining bars 95 as shown in Fig. 2.

The operation has been partly indicated. The crushed fuel enters by thepassage 18 and thence enters the first reduction chamber within thecasingll. The swinging hams mers 50 effectively reduce all substantialparticles to a finely divided condition. Any foreign matters, scraps ofiron etc., are rejected through the peripheral opening at the bottom ofthis chamber into the hollow receptacle 14. It will be noticed in Fig. 2that the lining plates 94 are omitted to the extent necessary'to admitthe foreign matter into the receptacle. From the first chamber thepulverized fuel is compelled to pass through the passages between thevanes 61 into the second reduction chamber. The axial progress ismaintained by suction at the fan end which may be supplemented by airinjection at the inlet end. The materials are whirled at high angularand linear speed and therefore under high centrifugal force. The vanes61 however obstruct the whirling motion. The forward component carries apart of the whirling flow into the spacesvbetween the vanes and anyheavy particles entering such spaces are caused to impact against thevanes, with a rejecting action tending to throw such particles back intothe first chamber. The result is that a certain percentage of thewhirling air is carried forward and with it only ofthe finer particlesof fuel, these being delivered into the second reduction chamber.

The system of alined rims or walls provided in connection with thenon-rotating and rotating elements constitute a substantially continuouswall or barrier which serves to confine the whirling and advancingmaterials to the peripheral portions or beating zone of the interior ofthe casing. This feature is believed to be novel irrespective of the useof the described vanes 61, 71 or 81, so long as some selecting orseparating device is introduced between the successive reduction units.The use of the closed webs or disks 55, 67 or 87 for either orboth thevanes and the heaters cooperate in confining the materials to theeripheral zone, because preventing the materials being shunted inwardtoward the axis and thus forward to escape the beating or separatingactions.

Referring to the first separating unit, com-' prising the vanes 61, thereduction of material is not merely by impact but also by attrition asthe particles roll or slide along the surfaces of the vanes orenclosingrims. In Fig. 5 the whirling motion is diagrammatically illustrated bythe long arrows a and the forward progress by the short arrow 1). Theproportions are not intended to represent actual conditions as thewhirling or peripheral component may be many times as great as theprogressing or axial component. The resultant of the two components isan inclined or helical motion or travel, and this tends to carry theparticles slightly into the separation spaces, with the results asstated. As shown in Fig. 1, in each separating unit the forward passagesbetween the vanes are preferably tapered by reason of the flared shapeof the inner walls or rims.

-The action at each separating device is a selective separation bypassing the finer and rejecting the coarser particles. The combinedwalls 66, 56, 76, 56' and 86 form a barrier compelling all particles toundergo the selective separation, and in this action the closed webs ordisks 67, 55 and 87 cooperate, especially the webs of the barrier wallsat each set of vanes.

Between the casing and the combined barrier walls, the enclosedperipheral space may be considered as an annular zone in which thebeating and separating actions occur, and the purpose of the barrier isto confine the whirl- 1ng materials to this annular reduction zone.

In the second reduction zone the heaters are shown in two series and instaggered relation, owing to which any substantial particle passingforwardly through this zone is subjected to reduction not only at thefirst series or hammers 58, but a ain at the second series 59, thusmultiplying t e reduction action.

At the second separating point the vanes 71 are shown substantiallyinclined at what may be termed a reverse slant or backward incline. Thisgives a far more effective separating of excluding action sinceparticles of appreciable momentum are positively thrown back by thecamming action of the backslanted surfaces. In this way any particlesthat stubbornly resist reduction are repeatedly thrown back into thereduction chamber and undergo repeated attrition before advancmg.

The vanes 71 are shown in Fig. 5 at an angle of about 45, but they mayhe at a lesser or greater angle. For example, they may be at the greaterangle of 60 as shown at 61 in Ifig. 6, giving a more thorough separatingactron. Diagrammaticall are shown in Fig. 6 the arrows at and b wit theresultant arrow 0 indicating in a general way the motion of theparticles and making clear the action of the vanes 61 in throwing backany particles too heavy to be floated forwardly with the air streamdiverted by the vanes. Only impalpably fine coal is carried forwardlybegween the vanes into the next reduction cham- A modified arrangementis that shown in Fig, 7 wherein the vanes 61 are of double inchneshape,like arrow heads, directed toward the whirling motion. The first part ofeach vane gives the described separating and re ect1ng action, while thesecond part tends to expedite the forward progress of the air and finestparticles, thus preventing back pressure in the succeeding chamber andfacilitating progress through the pulverizer. In each case the first orentrance part of the vane is back slanted to afford positive separatlngaction.

The final heaters 58 and 59 are similar to 58 and 59, but are morenumerous so as to give a greater number of impacts at this final stage.The final vanes-81 and 81" afford a separating action, while theextensions 81 or some of them facilitate the drawin inwardly, toward theaxis, against centri ugal force, of the fuel-laden air to the contractedoutlet 24 delivering into the fan chamber- The web 87 cooperates inthis, and together with its outer portion, formed as the barrier 86,compels the whirling materials to advance only through the separatingvane unit 81, 81.

, There has thus been described a pulverizinvention to such featuresexcept to the extent set forth in the appended claims.

What is claimed is:

1. A pulverizing machine having a' substantially cylindrical casing, arotary reducing device operating in a peripheral annular zone in thecasing, a set of separating vanes V located beyond the heating device insaid annular zone, and a barrier wall confining the whirling materialsto such zone and compelling them to undergo the reducing and separatingactions. v

2. Alpulverizing machine having a casing, and means for "maintainingprogressive advance of air therethrough, rotary heating means operatingin an annular zonewithinthe casing and adapted to cause whirling of theair and material to be pulverized, a relatively stationarydevicesucceeding the beat ing means comprising whirl obstructing vanesin such annular zone, and walls confining the whirling materials to theannular zone. a

3. A pulverizing machine having a casing, and/means for maintainingprogressive advance of air therethrough, a rotary beatingdevice adaptedto cause whirling of the air and material to be pulverized, a secondsuch beating device spaced from the first, a relatively stationarydevice between the beating devices comprising means for selectivelyseparating and throwing back heavier particles, and a barrier wallconfiningthe whirling materials to the peripheral space within thecasing;

4. A machine as in claim 1 and wherein is a transverse wall extendingacross and closing the space inside the annular zone and vanes.

5. A machine as in claim 3 and wherein is a closing diskextendingacrossthe space -from one side to the other inside the barrierwall.

6. A machine as in claim 3 and wherein.

comprising a disk on the shaft, a barrier wall at the disk periphery,and beaters exterior to the barrier wall, a selectively separatingdevice succeeding the beating unit and having a closed wall extendingsubstantiallyto'the shaft and a barrier wall at the periphery, thereof.in alinement with the first barrier wall, whereby the whirling materialsare confined to the peripheral space within the casing, and therebycompelled to undergo beating and separating actions.

8. A pulverizer comprising a power shaft, a concentric casing, acircular series of separating elementsor vanes extending partiallyinwards from the casing and enclosing flow spaces, a barrier wallclosing the inner sides of such flow spaces, a closed disk extendingfrom the shaft to the barrier wall, and a reducing device on the shaftimmediately in advance of the barrier wall and disk.

9. A pulverizing machine having a casing, and means for maintainingprogressive advance of air therethrough, a rotary beating unit adaptedto cause whirling of the air and material to be pulverized, and arelatively stationary unit succeeding the beating unit comprising vanesarranged at .a slanting angle to cause whirling particles of excessivesize to be selectively separated and diverted back towards the heatingunit. 10. A pulverizing machine having a casing, and means formaintaining progressive advance of airtherethrough, a rotary heatingunit adapted to cause whirling of the air and material to be pulverized,and a relatively stationary unit succeeding the heating unit comprisingvanes arranged at a slanting angle to cause whirling particles ofexcessive size to be selectively separated and diverted back towards thebeating unit while the finer. particles are carried forward with the airstream between the separating vanes.

11. A pulverizing machine having'a casing,

and means for maintainng progressive advance of air therethrough, ashaft inthe cas ing, a rotary heating unit on the shaft adapted to causewhirling of the air and material to be pulverized, a second such unitspaced from the first, and a relatively stationary unit between thebeating units comprising vanes arranged at such a slanting angle thatheavy whirling particles impacting the vanes are selectively separatedand diverted back.

12. A-pulverizing machine having a casing, and means for maintainingprogressive advance of air therethrough, a rotary heating unit adaptedto cause whirling ofthe air and material to be pulverized, and arelatively stationary vane unit succeeding the beating unit comprisingwhirl obstructing vanes, a second beating unit succeeding the vane unit,and a second vane unit succeeding the second beating unit, the vanes ofthe second unit having a greater back slant than those of the first unitto give a finer selective separation of heavier particles.

13'. A pulverizing machine as in claim 12 and wherein the first vanesare axially ar-' ranged and the following vanes at a decided back slant.

14. A pulverizing machine as in claim 12 and wherein the finalvanes,following the final heating unit are inclined, and. continued as axialwalls extending to the casing outlet.

15. A pulverizing machine as in claim 9 and wherein the vanes areV-shape, the first portion slanted as stated, the second portionreversely slanted to assist progress of air and finer particles.

16. A pulverizing machine as in claim 10 and wherein is a barrier wallbetween which and the casing is an annular zone in which the vanes arelocated.

17. A pulverizing machine as in claim 12 and wherein is a barrier wallconfining the whirling materials to the annular zone in which the vaneunits are located.

18. A pulverizing machine having a substantially cylindrical casing, andmeans for maintaining longitudinal advance of air therethrough, acentral shaft for high speed rotation, a plurality of rotary beatingunits on said shaft adapted to operate in the peripheral annular zone insaid casing to cause whirling of the air and material to be pulverized,a relatively stationary device in the annular zone between two beatingunits comprisin a system of whirl obstructing vanes exten ing inwardlyfrom the casing and arranged at a slanting angle to divert the heavierparticles reversely, and a barrier wall spaced concentrically withinthecasing and enclosing said peripheral annular zone whereby theprogressing materials are confined to said zone subject to the action ofthe heating units and the diverting vanes.

19. A pulverizing machine comprising a casing having a centraldischarge, a rotary reducing unit therein operating in a peripheralannular zone, a vane unit following the reducing unit comprising a setof vanes m such zone for separating and selectlvely throwing backheavier particles while permitting the advance of air and finerparticles between the vanes, rier preventing the materials (passinginwardly from such zones, a seeon such redu'cing rating vanes extendedaxially and then inunit, and a final vane unit, comprising sepawardly tothe central discharge and having a barrier confining the materialsto-the 'an- 'nular zone between the vanes and extended inwardly toprevent access to the discharge except through such zone and along theinward extensions of the vanes.

20. A pulverizing machine having a substantially cylindrical casing, andmeans for maintaining longitudinal advance of air therethrough, acentral shaft for high speed rotation, a beatin device on said shaftoperating in an an ar zone to cause whirling of tie air and material tobe pulverized, a set of separating vanes succeeding said heating deviceextendin between the casing and a barrier wall in suc annular zone,suchbarrier wall, and a disk closing the space between such barrier walland the shaft, a second beating device on the shaft, having said vaneshaving a bara barrier wall in alinement with the first barrier wall, asecond set of separating vanes succeeding the second beating devicearranged at a back slant to throw back heavier particles, and having abarrier wall in alinement with the second barrier wall.

21. A pulverizing machine having a cylindrical casing with centraloutlet to a suction fan, a central shaft, one or more rotary devices onsaidi-shaft with peripheral heaters adapted to cause whirling of the airand material to be pulverized, a stationary system of whirl obstructingperipheral vanes succeeding the final heating device, the same havingcontinuations extended toward the shaft to carr the flow to the casingoutlet, and a close wall forming a barrier within the peripheral vanesand extended inwardly toward the shaft.

22. A machine as in claim 21 and wherein the closed wall is spaced fromthe casing end wall to afford assages between the vane continuations, anis curvedly extended toward Elie outlet to afford a smooth delivery tothe In testimony whereof, this specification has been duly signed by:

PAUL ARTHUR HIRSCH.

CERTIFICATE or CORRECTION.

Patent No. 1,744,895. Granted January 28, 1930, to

' PAUL ARTHUR HIRSGH.

it is herebycertified that error appears in the printed snecificationcithe above numbered patent requiring correction as follows: Page 6,line 44, claim 19. for the werd "zones" read "zone"; same'page andclaim, strike out lines 45 to 47 inclusive, and insert instead Yunit,and a final vane unit, comprising separating vanes extended axially andthen inwardly to the central discharge and having"; and that the saidLetters Patent should be read with these corrections there in that thesame may conform to the record of the case in the Patent Office.

Signed and sealed this 20th day of May, A. D. 1930. e

M. J. Moore,

7 (Seal) Acting Commissioner of Patents.

